A “Frontline” documentary to air Tuesday night about the government’s thus-far elusive efforts to nail SAC Capital Advisors founder Steve Cohen on insider trading charges promises some exclusive video on a deposition given by the billionaire investor that was obtained in a cloak-and-dagger method reminiscent of Watergate.

The video was given to Nick Verbitsky, the director of the documentary, by an anonymous tipster who contacted him via text.

After some back and forth, a copy of Cohen’s two-day deposition loaded onto a USB drive was left across the street from Frontline’s New York City office, cradled between two bars of scaffolding.

Verbitsky told The Post he wasn’t “exactly sure” how the person with the video got wind of his interest, but said he had called the person who shot the video and the transcription company, but “no one had it.”

Those people, in addition to the plaintiff and defendants’ lawyers, knew he wanted it.

The video shows Cohen being evasive when asked about the rules on insider trading, saying he understood them to be “very vague.”

When asked if he thought there was ever a time it would be okay to trade on material, non-public information, Cohen indicated there was.

When he was arrested last year, Martoma — who is alleged to have had a 20-minute phone conversation with Cohen to give him inside information that led to a $276 million illegal trade by SAC — appeared to be the government’s best shot at indicting Cohen.

But so far, Martoma has refused to cooperate with the government and turn on his former boss. Cohen has not been charged with any crime.

The documentary doesn’t offer any insight into that trade, but it does have never-before seen video footage of a deposition Cohen gave during a lawsuit brought by Fairfax Financial Holdings against several hedge funds, including SAC, that shorted the company’s stock.